Providing forensic and traditional engineering services to the legal profession and insurance industry, we are one of Ireland’s leading firms of consulting forensic engineers, with a vast depth and breadth of corporate experience extending over more than 40 years, and with a combined total of more than 80 years’ individual experience across three engineers.

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The Association of Consulting Forensic Engineers (then Association of Litigation Engineers) was founded in December 1982 by a group of seven Consulting Engineers who practiced as Expert Witnesses in Ireland. The Memorandum of Association defines the role of a Consulting Forensic Engineer as a person who undertakes evidential engineering investigations.

Members of the Association are Chartered Engineers (or equivalent status) who practise as Consulting Engineers either individually or as Partner in a Practice of Consulting Engineers.


Peter Johnston

Principal, Chartered Engineer

Peter is a graduate of Trinity College, Dublin, holding degrees in maths (BA) and mechanical and manufacturing engineering (BAI). He is a chartered member of Engineers Ireland (CEng MIEI). He holds an International Diploma in Occupational Health and Safety from the UK National Examination Board in Occupational Safety and Health (IDip NEBOSH). He holds Certificates of Competence in both occupational and environmental noise assessment. Now the company principal, Peter has been with the company since 1981, and has undertaken thousands of occupational, public liability and road traffic accident investigations, preparing reports and giving expert witness evidence in the courts at all levels over the last 35 years. He has also reported on a variety of noise matters, both occupational (hearing loss) and environmental (noise nuisance, planning). He has also undertaken construction projects, and building survey work.


Lloyd Semple

Chartered Engineer

Lloyd is a graduate of the Dublin Institute of Technology, Bolton Street, Dublin. He is a Chartered Member of Engineers Ireland (CEng MIEI). He joined the practice in 2011, bringing substantial experience in all aspects of structural engineering design work and project management. He holds postgraduate diplomas in Applied Building Materials & Conservation, and in Fire Safety Practice, both from Trinity College, Dublin, and a postgraduate Certificate in Thermal Performance Modelling for buildings, from DIT, Bolton Street. Since joining the practice, Lloyd has been involved in both building defects analysis and structural survey work, and in a wide variety of accident investigation work, including occupational and public liability accident investigations

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Nikki Thuillier

Chartered Engineer

Nikki is a graduate of Birmingham City University with an honours degree in Mechanical Engineering. She is a chartered member of Engineers Ireland (CEng MIEI) and holds Associate Membership of the Institute of Mechanical Engineers in the UK. She holds an MSc in Forensic Engineering and Science from Cranfield University. Prior to joining the practice, she served thirteen years as an Engineer Officer in the Irish Defence Forces, having previously worked for Jaguar Land Rover (Coventry), Timoney Technology (Navan) and Johnson & Johnson Vision Care (Ireland) (Limerick).  With over fifteen years in the industry, Nikki brings to the practice her experience in project management, health and safety and risk assessment, fire protection, as well as bridge assessment and construction and building services engineering design.


David Semple


Having founded the practice in the 1970s, and after leading the practice with Peter Johnston for many years, and then acting as a Consultant from 2016 to 2021, David has now retired from practice.